Centrifugal compressor



' May 12, 1925.

A. A. BROOKS CENTRIFUGAL COMPRESSOR 2 Sheets-Shet 1'- Filed May 16, 1922 [five/76w; fl/fi'ed .27. Brooks,

HA5 flt ornay an improved Patented May 12, 1925.

UNITED STATES PAT NT O E v ALFRED A. BROOKS, 0F WELLSVILLE, NEW YORK, ASSIGNOR '20 GENERAL. ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CENTBlFUGAL COMPRESSOR.

Application filed Kay 16, 1922. ami-m. 561,397.

To all whom it may concern:

Be it known that I, ALFRED A. BROOKS, a citizen of the United States, residing in Wellsville, in the county of Allegany, State of New York, have invented certain new and useful Improvements in Centrifugal Compressors, of which the following is a specification.

The present invention relates to centrifugal compressors, such as air or gas compressors and particularly centrifugal compressors having axial inlet impellers and stationary inlet guide vanes for directing the fluid being pumped into the eye of the impeller. In such compressors the impeller vanes are arranged around the" hub of-the impeller and extend in a generally radial direction. They receive the fluid being pumped at their radially inner ends and discharge it at their radially outer ends, i. e., at the periphery of the impeller.

The object of my invention is to provide structure or arrangement of stationary inlet guide vanes for compressors of this type and for a consideration of what I believe to be novel and my invention attention is directed to the following description and the claims appended thereto.

In the drawing, Fig. 1 is a face view of the inlet side of an inlet or guide vane structure embodying my invention; Fig. 2 is a similar view of the discharge or exit side; Fig. 3 is a sectional View of a compressor provided with stationary guide vanes embodying my invention; Fig. 4 1s a perspective view of a guide vane, and Figs. 5, 6 and 7 are enlarged diagrammatic sectional views taken on lines 5-'-5, 66 and 7 7 respectively, of Fig. 3.

Referring to the drawing, 10 indicates the casing of a compressor having the usual discharge scroll 11 which receives the air from the periphery of the impeller and conveys it to the discharge opening. Suitably mounted in casing 10 is a shaft 12 upon which is mounted an impeller comprising a hub 13 and radially extending vanes 14. An 1mpeller which receives fluid to be pumped on 0th sides is illustrated, the entrance edges of the vanes being indicated at 15. At the entrance edges of the impeller are statlonary inlet guide vanes 16 carried by s aced concentric rings 17. The entrance e ges of the patent statutes,

inlet guide vanes are indicated at 18 and the exit edges at 19.

IVith-an impeller of'this type the velocity of the radially outer portions of its entrance edges 15 is greater than that of the radially inner portions, there being a gradually increasing velocity from the inner edge radially outward due to the increasing diameter. Also with stationary inlet guide vanes the absolute velocity developed by the fluid being pumped is the same at all points at the exit edges of the inlet guide vanes because all points in that plane are in free communication with each other and are subject to the same drop in pressure produced by the impeller.

According to my invention I so shape the stationary inlet guide vanes that the resultant relative velocities between the absolute Velocity of the fluid leaving the exit edges of the guide vanes and the velocities of the entrance edge of the eye of the impeller is at all points axial. This is illustrated in Figs. 5, 6 and 7 where in the diagrams W is the velocitv of the entrance edge of the impeller at the particular point on which the section is taken, V is the absolute velocity of the fluid being pumped at the exit edges of the inlet guide vanes, and R is the resultant air velocity relative to the impeller entrance edge. To obtain this result. the stationary guide vanes take the form of warped surfaces somewhat resembling helicoidal surfaces. One of these vanes is shown in perspective inFig. 4'. From the sections shown in Figs. 5, 6 and 7 it will be seen that the discharge angle of the entrance vanes is least at the hub and gradually in creases toward the outer end.

Viewed from a different aspect the stationary inlet guide vanes are so shaped or warped as to give a graduation of the tangential component of the exit velocity from them which corresponds to the velocity of the entrance edge of the impeller.

By this arrangement the fluid being pumped is directed evenly and without shoe to the impeller and in a direction to give the highest efficiency in operation.

In accordance with the provisions of the I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that' the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, 1s:-

1. The combination with a centrifugal compressor having an impeller which has an axially facing inlet at its central portion and a peripheral discharge, of stationary guide vanes for directing fluid to the inlet, said vanes being twisted to provide helicoidal surfaces such that the resultant relative velocities between the absolute velocity of the fluid at the exit edges of the vanes and the velocities at the entrance edges of the eye of the impeller are substantially axiaL 2. A centrifugal compressor having stationary inlet guide vanes which are Warped from their inlet to their exit edges to such an extent that the resultant relative velocitiesbetween the absolute velocity of the fluid at the exit edges of the vanes and the velocities at the entrance edges of the eye of the impeller are substantially axial.

3. A centrifugal compressor having stationary inlet guide vanes which are Warped from their inlet to their exit edges to such an extent that the tangential component of the exit velocity at any point along the discharge edge of the vanes corresponds substantially to the velocity of the corresponding point at the entrance edge of the impeller.

In witness whereof, I have hereunto my hand this 12th day of May, 1922.

ALFRED A. BROOKS.

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